Centrifugal switch



Feb. 9, 1932. oRRls 1,844,674

CENTRIFUGAL SWITCH Filed June 2 1929 Irv/enter:

Marvin L. NOPPI 13y m \l is WGliowney.

Patented Feb. 9,1932

MARVIN L. NORRIS, OI FORT WAYNE, INDIANA, ASSIGNOB 'ro GENERAL mac-rare COMPANY, A CORPORATION OI NEW YORK cammoeai. swncn Application filed June 21,

My invention relates to centrifugal switches of the type generally employed for controlling the clrcuits in split phase induc? tion motors, repulsion induction motors, or other electrical devices in which it is desired to controlthecircuits thereof, or other cir cuits in accordance with the speed of rotation of the switch.

The object .of my invention is to provide a centrifugal switch which is of simple construction, reliable in operation and which can be readily manufactured. I accomplish this by providing a centrifugal switch including weights which are pivotally supported and connected together, an arrange- 1 ment for variably resisting outward movement of the weights, and a circuit controlling device arranged to be actuated by the weights.

urther objects and advantages of my invention will become apparent as the following descri tion proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In the drawings Fi .1 is an end view of a centrifugalswitch em dying my invention; Fi 2 is a side view of the structure shown in 'g. 1; Fig. 3 is a perspective view part1 broken away showing my improved centri u al switch, and Fig. 4 is a perspective view 0% the stationary insulating ring forming part of the circuit controlling device of the switch shown in Figs. 1 to 3, inclusive.

Referring to the drawings, the centrifugal switch which I have illustrated as an example of one manner of carrying out my invention includes centrifugally actuated weights which are connected to a circuit-controllin device by pull rods extending axially 'of the shaft on which the switch is mounted in such manner that when the weights attain sufiicient speed of rotation to move them outwardly against the force .ofthe sprin which normally retain them adjacent the axis of rotation of the shaft, the pull rods actuate the controlling device so as to make or break the contacts of the switch as may be desired.

1829. Serial No. 872,675.

The centrifugal switch shown in the drawings includes weights 10 which are made of punchings riveted together, as indicated at 11, and are made to fit about the shaft 12 intermediate the ends thereof as shown in the drawings. The weights 10 are riveted to arms 13 as at 14, which are pivotally mounted at 15 on a bracket 16 arranged on the shaft 12. In order to move the weights 10 toward and away from each other in unison I connect the arms 13 together by gear teeth 17 inrieshing with each other, as indicated in It is desirable that the outward movement of the weights 10 should be variably resisted by a force which decreases and which assists the outward movement ofthe weights after a predetermined outward movement thereof. I do this by providing projections 18 on the arms 13 which are close to the line of centers of the pivotal supports 15 when the weights 10 are in their position adjacent the shaft shown in the drawings, and connecting the projections by tension springs 19. By arranging the projections adjacent the line of centers of the .pivotal supports 15, when the weights 10 move outwardly, the projections 18 are swung to the right in Fig. 2 and approach the line of centers of the pivotal supports 15, reaching this line of centers after the weights have moved a portion of the range of their outward movement. Further outward movement of the weights causes the projections 18 to move to the right of the line of centers of pivotal supports 15, so that the sprin 19 exert a force which assists the weights in their outward movement and causes the weights to move suddenly outwardly to their extreme position. The

g springs 19 are designed to exert such force on the projections 18 that the weights 10 swing them over the line of centers, of the projections 15 at substantially full speed of the shaft 12, so that the centrifugal device gsacts very quickly at this speed to actuate the circuit-controlling device of the switch/ The circuit-controllin device of my imroved switch may be 0% any suitable form, at I prefer to make the same of the construction illustrated in the drawings. This construction includes a stationary flanged insulating ring 20 having contact 21 which is secured tothe ring by an arcuate spring finger 22 which is supported in spaced relation to the flanged insulating ring by bushings 23 and screws 24. Another contact25 is supported on the flange 20 of the insulating ring by asprmg finger 26 which is attached to the flange 20 by screws 27. An annular conducting spring yoke 28 is attached to the flanged insulating ring 20 by screws 29 and is formed with an opening 30 adapted to receive an insulating actuating collar 32 rotatable with the shaft 12, on which the other elements of the centrifugal switch are mounted, having a shoulder 31 adapted to engage the yoke. Contacts 33' and 34 are attached to the yoke 28, which supports them in operative relation to the contacts 21 and 25 respectively, and which serves to connect them to an external circuit.

7 These contacts are arranged so that when the collar 32 is at the extreme right of its-range of movement axially of the shaft 12, as shown in the drawings, the contacts 34 and 25 are in engagement with each /other. When the shaft 12 attains a predetermined speed sufficient to move the weights 10 to their extreme outward position the collar 32 is moved to its extreme position to the left of that shown in Fig. 2 and out of engagement with the yoke 28, which opens the contacts 34 and 25 and closes the contacts 33 and 21 so as to make and break the circuits of the switch. In this portion of the switch, which is its normal running position, the collar 32 is out of contact with the yoke 28.

In applying my centrifugal switch to a motor, for example, I prefer to arrange the bracket 16 on the shaft 12 against one end of the core structure 'of the motor rotor, which is indicated at 35, and arrange the insulating collar 32 on the shaft 12 slightly spaced from the other end of the core structure of the motor rotor indicated at 36. I then arrange a spring 37 between an internal shoulder 38 in the collar 32, and the end of the rotor core structure indicated at 36, which tends to urge the collar 32 to its position to the extreme right of its range of movement, as indicated in Figs. 2 and 3. I connect the arm 13 of the centrifugal device to the collar 32 by pull rods 39 which extend through openings in the core structure. One end of each of the pull rods is formed with a right angle bent adjacent the end thereof which fits in a slot 41 formed in the arm, the portion of the pull rod extending beyond the slot tending to hold the pull rod in place. The other end of eachof the pull rods extends into a recess 42 formed in the collar 32, and is bent at right angles, as indicated at 43, so as to engage a snap ring 44 arranged on the insulaltmg collar for retaining the pull rods in p ace.

' In the operation of the centrifugal switch which I have described, when the shaft 12 is started, the insulating collar 32 and the centrifugal device will be 'rotated therewith. When the shaft attains suflicient speed to move the weights 10 outwardly against the action of the springs 19, the projections 18 will be moved to the right of the line of centers of the pivotal supports 15, and the springs 19 will then assist in moving 'the' weights 10 outwardly so as to cause them to move to their'extremeoutward position very quickly. During the initial movement of the weights 10 the collar 32 will not be moved until the bent portion 40 of the pull rod 39 engages the end of the slot 41. In this way the collar 32 is moved in such a manner as to open the contacts 34 and 25 quickly. This outward movement of the weights is resisted by the springs 19 and also by the spring 37 arranged between the insulating collar32 and the end of the rotor core structure indicated at 36. When the weights 10 have moved to their extreme outward position the end of the collar 32 is moved against the end of the rotor core structure 36 and out of engagement with the conducting yoke 28 of the stationary member, of the circuit-controlling device. By this construction the insulating collar 32 runs entirely out of contact with the yoke 28 during normal operation of the motor. creases the force of the spring 37 is sufficient to swing the Weights 10 toward the shaft 12 against the action of the spring 19, which will at that time oppose the return of "the weights. and move the projections 18 over the line of centers of the pivotal supports 15, which moves the weights to their position adjacent the' shaft, as shown in the drawings. During this movement of the collar 32 the contacts 33 and 21 of .the circuit-controlling device will be broken and contacts 34 and 25 thereof will be closed.

Modifications of the particular embodiment of my invention which I have disclosed will occur to those skilled in the art, so that I do not desire my invention to be limited to the particular arrangement set forth, and I desire in the appended claimsto cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A centrifugal switch including weights. pivoted arms for supporting each of said weights, each of said arms having gear teeth meshing with each other to move said weights in unison, means for variably resisting outward movement of said weights, and a circuit-controlli'ng device actuated by said weights.

2. A centrifugal switch including weights, pairs of pivoted arms for supporting said weights, said arms of each weight engagin said arms of another weight for moving sai When the speed of; the shaft 12 de-.

weights in unison, springs connecting the arms of each weight to the arms of the other and arranged to variably resist outward movement of said weights, and circuit-controlling means arranged to be actuated by said weights.

3. A centrifugal switch including weights, means including arms for pivotally supporting said weights, said arms engaging each 19 other to move said weights in unison, a spring connecting said arms and arranged to move from one side of the other of the pivots for said supporting arms so as to resist outward movement of said weights for a portion of their range of movement and to assist movement of said weights for the remainder of their range of movement, a circuit controlling device, and means including a spring to return said weights toward their initial position upon a predetermined decrease in speed thereof for actuating said circuit-controlling device.

4. A centrifugal switch including a rotatable support, flat plates pivotally secured to tween their pivotal supports to move them in unison, weights carried by said plates, a spring connecting said plates at the side of their pivoted connection with said support adjacent said weights so as to resist the outward movement of said weights. said springs being arranged to be moved to the side of said pivoted supports remote from said weights upon a predetermined movement thereof so as to assist the outward movement of said weights and obtain a snap action, and a circuit controlling device actuated by said weights.

5. A centrifugal switch including a rotatable support, flat plates pivotally secured to said support and having gear teeth meshing with each. other between their pivotal supports to move them in unison, weights secured to said plates, projections on said plates extending transverselv of the main body thereof, springs carried by said projections for urging said weights toward their axis of rotation. said springs and projections being arranged at the side of said pivotal supports adjacent said weights so as to resist outward movement of said weights and being arranged to move to the side of said pivoted supports said support and engaging each other be-- shaft and acting on said rotatable collar for actuating said circuit controlling means.

7. In combination with a rotatable shaft, a centrifugal switch including a stationa ring arranged about said shaft, a rotatab e collar mounted and arranged about said shaft ad acent said stationary ring, contacts carried by said ring, an annular spring carried by said ring arranged between said collar and said ring to control circuits through said con tacts, and means including a centrifugal device carried by said shaft and acting on said rotatable collar for actuating said circuit controlling means.

In witness whereof I have hereunto set my hand this 19th day of June, 1929.

MARVIN L. NORRIS.

remote from said weights upon a predetermined outward movement thereof so as to assist the outward movement of said weights and obtain a snap action, and a circuit controlling device actuated by said weights.

6. In combination with a rotatable shaft, a centrifugal. switch including a stationary ring arranged about said shaft, a rotatable collar mounted on said shaft adjacent said stationa r' contacts carried by said r' means c a rriia d by said ring for controllin g a circuit through said contacts, and means meluding a'centrifugal device carried by said 

